1. Field of the Invention
The present invention relates to an improved method for producing pressure sensors comprising diaphragms and to diaphragms for said pressure sensors.
2. Prior Art
The invention relates to a diaphragm for a pressure sensor as generically defined by the preamble to the main claim.
In conventional metal diaphragms, especially for high-pressure sensors, the entire diaphragm, including the support elements, is preferably made in one piece of stainless steel. Because of the stringent demands made in terms of the properties of the diaphragms, production of the one-piece metal part requires complicated work steps such as turning, grinding, lapping and polishing to a high gloss. To further complete the diaphragm with sensor elements, a thin-film coating on the metal diaphragms is necessary in many cases.
The diaphragm according to the invention is advantageous because the diaphragm face can be made separately and economically as a part comprising a special steel band, and the required properties are assured in a simple way. For diaphragm thicknesses of approximately 0.4 to 1 mm (and optionally even greater), thickness tolerances of  less than 5% of the diaphragm thickness should be adhered to. The surface quality on the top side should have a value of Rz less than 0.1 xcexcm.
To make it simple to positionally fix the metal diaphragm, the diaphragm part stamped out of the special steel band has a fixation lug on its outside.
The diaphragm of the invention can also advantageously be produced in a group blank production process, in which a single sheet-metal part can include a plurality of support bodies and thus a plurality of diaphragms. The requisite production processes for the thin-film coating can advantageously be applied to all the diaphragm faces of the special steel band simultaneously.
Further advantageous embodiments are defined by the dependent claims.